gun for man's man. We're joined by one of america's leading psychologists. Michael welner. He consults on homicides around the u.S. And thanks for coming back to join us. That's interesting that selling bushmaster, calling it a watershed moment. You say we have to look at the mass killings as a social phenomenon. Yeah. I think it's easy to target the gun issue. And the gun issue is vulnerable. But I think only from one vantage point. And that is, if you take assault, high-capacity, high-rapid fire weapons and take them out of the equation. And look at all the mass shootings that happened this year, we see this is happening with greater frequency than ever before. What I'm telling you is, we're dealing with a population, the mass killer. One of the things that distinguishes that person is, once he decides he's going to do it, he's going to do it. If you can keep an assault rifle out of his hands, the body count will drop. And that's great. But the mass killings will continue to happen unless systemically we address it as a social phenomenon. And recognize there's things that promote it. For example, his picture on our screen and us even caring to go all the way back to find out what his grievance is. We'll talk about that in a moment. And things that enable and facilitate is isolating, alienating from the world, and killing children like he's in an arcade game. You say there's no question that the search for celebrity is part of this. Going out in a blaze of glory. You're actually recommending not covering this at all? Well, you know, words are important. I think celebrity, for some, like a breivik, in norway. He wants celebrity. He takes the pi he's ready for his close-up. You can't say this about this man. What you can say, what's the common thread of both? Irrelevance. What's the common thread of the mass killer? A grievance. But it's a grievance that's their grievance. That doesn't make it legitimate. I could say I have a grievance with you. I could just conjure something up because I'm resentful and alienated and you're looking at me funny. That doesn't legitimize it. What mass killers have learned, by watching a story such as ours, saying w going to find out everything about their life. We want to know why. Why? When he was alive, his mother and other people paid attention to his grievance. He has it. The police know it. It's a social phenomenon. My point is, what he's after is legitimacy. They want to go from irrelevance to hyperrelevance. Is there any way to target these mostly young men before they kill? Here's the pathway. The pathway is someone who starts out blaming others, resentful, and withdrawn. And over time, become increasingly withdrawn. And then, invested in the idea of blaming others. So, it's a person who becomes invested in the idea that everybody is responsible for their social awkwardness, for his sexual incompetence, man's man. Okay? And identifies with destruction and themes of destruction. It's masculinity because that person has failed. And over time, seeing stories about mass killers and hearing the dialogue being, we failed. The end point of that is, people deserved what they got. And when someone taps into that and has gone down that path, and it's a path. Once they've gone down that path and their life is going nowhere, they start to entertain the idea of adopting that as an ambition. And when that happens, it's a ticking process. They never stop. We have to find a way to block that path. There is a way. We have to eliminate it. And there are things that each one of us can do. Each one of us can do. First of all, what can parents do? Teach your children personal Teach our children resilience because teach them to understand when they fall down they can get back up. Teachers, teach in children the values, the values of volunteerism. Connecting to other people. Creating, instead of destroying. Neighbors, set an example of helping people who are suffering. We all have a responsibility. I'm sorry, that's all we have time for right now. Dr. Welner, thanks very much.

This transcript has been automatically generated and may not be 100% accurate.